The fruiting body of Antrodia camphorata (Polyporaceae, Aphyllophorales) is well known in Taiwan as a traditional Chinese medicine. It grows only on the inner heartwood wall of the endemic evergreen Cinnamomun kanehirai (Hay)(Lauraceae) in Taiwan. It is rare and has not been cultivated. The fruiting bodies have been used for treating of food and drug intoxication, diarrhea, abdominal pain, hypertension, itchy skin, and liver cancer. Very few biological activity studies have been reported hitherto.
Antrodia camphorata, also known as “niu-chang-chih” or “niu-chang-ku” in Taiwan, was recently reported as a new fungus species characterized by the cylindrical shape of its basidiospores appearing in fruiting bodies, weakly amyloid skeletal hyphae, bitter taste and light cinnamon resupinate to pileate basidiocarps, as well as chlamydospores and anthroconidia in pure culture. The growth of this new fungus species is extremely slow and restricted to an endemic tree species, Cinnamomum kanehirai Hay (Lauraceae), as the only host. The detailed characterization and taxonomic position of Antrodia camphorata were described in Wu, S.-H., et al., Antrodia cinnamomea (“niu-chang-chih”), New combination of a medicinal fungus in Taiwan, Bot. Bull. Acad. Sin. 38: 273-275 (1997).
In Taiwanese folk medicine, the fruiting bodies of Antrodia camphorata are believed to have certain medical effects. According to the traditional way, the fruiting bodies are ground into dry powder or stewed with other herbal drugs for oral uptake to treat conditions caused by poisoning, diarrhea, abdominal pain, hypertension, skin itches and liver cancer. However, few pharmacological or clinical studies in these aspects have appeared in literature to date. Because of the stringent host specificity and rarity in nature, as well as the failure of artificial cultivation, “niu-chang-chih” is very expensive in Taiwan. In recent years, the fruiting bodies of this fungus with high quality have been sold at an extremely high price of around U.S.$ 15,000 per kg.
Oxidative stress including the generation of reactive oxygen species (ROS) can be implicated as a cause of hepatic fibrosis (M. Chojkier et al., Stimulation of collagen gene expression by ascorbic acid in cultured human fibroblasts, A role for lipid peroxidation, J. Biol. Chem. 264 (1989), pp. 16957-16962. and I. Shimizu, Antifibrogenic therapies in chronic HCV infection. Curr Drug Targets Infect Disord 1 (2001), pp. 227-240). It has been reported that hepatocytes, which are undergoing oxidative stress, release ROS that stimulate hepatic stellate cell (HSC) proliferation and transformation into α smooth muscle actin (α-SMA)-positive myofibroblast-like cells (G. S. Baroni et al., Fibrogenic effect of oxidative stress on rat hepatic stellate cells, Hepatology 27 (1998), pp. 720-726). These HSCs are referred to as activated cells and are responsible for the abnormal extracellular matrix (ECM) proteins during hepatic fibrosis to cirrhosis. Transforming growth factor-β (TGF-β) is a major fibrogenic cytokine, regulating the production, degradation, and accumulation of ECM proteins in hepatic fibrogenesis (A. Casini et al., Regulation of extracellular matrix synthesis by transforming growth factor β1 in human fat-storing cells, Gastroenterology 105 (1993), pp. 245-253). This cytokine induces its own expression in activated HSCs, thereby creating a self-perpetuating cycle of events, referred to as an autocrine loop. TGF-β gene expression correlates with the extent of hepatic fibrosis (A. Castilla et al., Transforming growth factors β1 and α in chronic liver disease. Effects of interferon α therapy. N. Eng. J. Med. 324 (1991), pp. 933-940.), and an increased production of ROS such as H2O2 in fibrotic livers is associated with the up-regulation of TGF-β (E. R. Garcia-Trevijano et al., Transforming growth factor β1 induces the expression of α1(I) procollagen mRNA by a hydrogen peroxide-C/EBP β-dependent mechanism in rat hepatic stellate cells, Hepatology 29 (1999), pp. 960-970).
Fibrotic diseases are characterized by excessive scarring due to excessive production, deposition, and contraction of extracellular matrix. This process usually occurs over many months and years, and can lead to organ dysfunction or death. Examples of fibrotic diseases include diabetic nephropathy, liver cirrhosis, idiopathic pulmonary fibrosis, rheumatoid arthritis, fibrosarcomas, arteriosclerosis, and scleroderma (systemic sclerosis; SSc). Fibrotic disease represents one of the largest groups of disorders or which there is no effective therapy and thus represents a major unmet medical need. Often the only redress for patients with fibrosis is organ transplantation; since the supply of organs is insufficient to meet the demand, patients often die while waiting to receive suitable organs.
Oxidative stress is associated with liver fibrosis and activation of hepatic stellate cells either directly or through paracrin stimulation by injured hepatocytes. Factors increasing reactive oxygen species (ROS) generation may also be involved in stimulation of excessive matrix production in vivo. Increase in hydrogen peroxide production leads to activation of a potent profibrogenic mediator TGF-β, supporting the idea that oxidative stress has important roles in fibrogenesis (Mehmet R. M., et al., The effect of taurine treatment on oxidative stress in experimental liver fibrosis, Hepatology Research, 28, 207-215 (2004).
TGF-β induces fibroblasts to synthesize and contract ECM, this cytokine has long been believed to be a central mediator of the fibrotic response TGF-β1 triggered enhancement of α-SMA and collagen type I expression.
The discovery in 1987 that nitric oxide (NO) accounted for the bioactivity of endothelium-derived relaxing factor rapidly led to an explosion of information on the physiological and pathological roles of this molecule. Although most well known for its physiological roles in vasorelaxation, neurotransmission, inhibition of platelet aggregation, and immune defense, NO also acts as an intracellular messenger for various cells in almost every system in the body (Peeyush and Chandan, Lancet Oncol 3:149, 2001).
Nitric oxide, this highly reactive free radical agent is synthesized from L-arginine by nitric oxide synthase. It acts in both the intercellular and extracellular environment and is believed to be a regulatory molecule in a variety of soft tissues including articular cartilage, ligament, tendon, skeletal muscle and bone. It is induced during tendon healing in vitro.
It appears that there is a dose-dependent effect upon its contribution to fibroblast production of collagen. There is also a site-specific effect with the anterior cruciate ligament-derived fibroblasts capable of producing more nitric oxide than from cells derived from the medial collateral ligament. Manipulation of nitric oxide production has been thought to help accelerate repetitive overuse tendon injury and tendinosis. The role of nitric oxide in the incorporation of an ACL graft remains under investigation through studies using transfection of cDNA for nitric oxide synthase (Deehan et al., J Bone Joint Surg 87(7):889, 2005).
Nitric oxide (NO) is integral to many biological processes including the control of blood pressure, protection against microbial infection and neurotransmission. Additionally, it appears to be a potent cytotoxin to tumor cells. Among its mechanisms of action on malignant cells, nitric oxide appears to inhibit DNA synthesis and mitochondrial respiration in vitro. It induces programmed cell death or apoptosis in these cells. Unfortunately, NO itself is difficult to administer as it is a highly reactive gas. It also causes hypotension if administered systemically. These limitations have prevented its use to date as an antineoplastic agent.
Generation of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) is a cardinal feature of inflamed tissues including those of the gastrointestinal tract. iNOS overexpression with high levels of NO generation provides a plausible link between inflammation and cancer initiation, progression, and promotion. NO is involved in a number of biological actions including cytotoxicity of phagocytic cells and cell-to-cell communication in the central nervous system. NO is also involved in the immune response (inducible NOS or iNOS), smooth muscle relaxation (endothelial NOS or eNOS), and neuronal signaling (neuronal NOS or nNOS).
Treatment of overuse tendinopathy using transdermal nitric oxide-generating agents is disclosed in U.S. Patent Application Pub. No. 2005171199. Use of nitric oxide scavengers to treat side effects caused by therapeutic administration of sources of nitric oxide is disclosed in U.S. Pat. No. 6,596,733. Use of products that release nitric oxide in vivo to treat or prevent infectious diseases in humans or animals is described in Germany patent application Pub. No. DE10303196 A1. Nitric oxide (NO) synthase inhibitor to treat or prevent Type II diabetes is described in Australia patent application Pub. No. AU4865800 A. Use of nitric oxide-releasing agents to treat impotency is disclosed in U.S. Pat. No. 6,290,981. Modification of nitric oxide activity to treat fas-induced pathologies is mentioned in PCT publication no. WO9903462 A1. Combined use of angiotensin inhibitors and nitric oxide stimulators to treat fibrosis is described in U.S. Pat. No. 6,139,847 A. Blocking induction of tetrahydrobiopterin to block induction of nitric oxide synthesis is disclosed in U.S. Pat. No. 6,274,581.